One application of an RL circuit

One application of an RL circuit is the generation of time varying high voltage from a low-voltage source, as shown in Figure P32.26.
(a) What is the current in the circuit a long time after the switch has been in position a? (b) Now the switch is thrown quickly from a to b. Compute the initial voltage across each resistor and across the inductor.
(c) How much time elapses before the voltage across the inductor drops to 12.0 V?